textproduct: Rapid City

KEY MESSAGES

- Cooler weather is sliding into the area today so highs this weekend will be cooler than it has been.

- Elevated to near-critical fire weather conditions today with a RED FLAG WARNING in effect for Weston County down across the southwestern South Dakota plains/southern Black Hills until 7PM MDT.

- The next organized storm system is expected this weekend, with the best chance of showers and storms Sunday night.

DISCUSSION

(This Afternoon Through Thursday) Issued at 133 PM MDT Fri Sep 11 2026

Cooler weather is settling into the region today. It's being driven into the area by strong northerly to northwesterly winds. Highest reported wind gusts (as of 1PM) have been upwards of 40 to 50 mph. For tonight, winds will slowly diminish through this evening but speeds will really decrease mainly after 9PM. Isolated rain and thundershowers are possible in the area that stretches from NE WY to NW SD later this afternoon through tonight. Severe weather is not expected and rain amounts won't add up to much.

Looking ahead to the weekend, temperatures will be at or below normal for this time of year with highs reaching the upper 60s to 70s. Winds will slowly swing back to the east and southeast on Saturday with wind speeds really increasing Sunday, afternoon gusts will be upwards of 30 to 45 mph, strongest speeds in the SD plains.

Isolated rain and thundershower chances return to the SD plains Saturday into Saturday night but amounts will be on the lighter side, mainly less than a quarter inch if anything. But Sunday into Monday, a passing upper level trough north of the CWA will track eastward. At the surface, low pressure will develop Sunday afternoon and likely travel northeast. As it does, thunderstorms are likely to track through the area late Sunday into Sunday night. Some of those storms could be strong to severe. The SPC and machine learning severe weather models are highlighting a marginal risk of severe weather. Rainfall amounts Sunday into early Monday will be mainly less than a half inch with locally higher amounts possible.

Next week is looking dry with low-end chances for precip late in the week with highs near or below normal for this time of year.

AVIATION

(For the 18Z TAFS Through 18Z Saturday) Issued At 1109 AM MDT Fri Sep 11 2026

VFR conditions are expected through the TAF period. Gusty northwesterly to northerly winds will continue across western SD and northeast WY behind the cool front, with gusts up to 30 to 35 kts. Isolated showers/thunderstorms are possible in the late afternoon and early evening across northeastern WY and portions of western SD. Another wave of showers and storms will be possible during the overnight hours for northwest SD. Confidence in storms impacting KGCC is still too low to include TEMPO/PROB30 at this time. If showers/storms develop, expect gusty/erratic winds associated with them. Winds will slowly diminish late overnight into the early morning Saturday (~12/10z).

FIRE WEATHER

Issued At 133 PM MDT Fri Sep 11 2026

A RED FLAG WARNING is in effect for SW SD and parts of NE WY until 7 PM MDT this evening. This is for strong, gusty northerly winds and relative humidity down to 12 to 18 percent.

Looking ahead through the weekend, cooler weather is expected with afternoon temps in the 60s to 70s. RH values will bottom out around 30 to 50 percent. Wind gusts will be strong again tomorrow (Saturday) for areas south and southwest of the Black Hills. Sunday will see more widespread gusty winds in the WY and SD plains. Similar weather expected next week.

UNR WATCHES/WARNINGS/ADVISORIES

SD...Red Flag Warning until 7 PM MDT this evening for SDZ321-322-325- 326-332-333. WY...Red Flag Warning until 7 PM MDT this evening for WYZ317.